Algal blooms and climate anomalies in north‐east New Zealand,August ‐December 1992 |
| |
| Authors: | Lesley L Rhodes Allison J Haywood W J Ballantine A Lincoln MacKenzie |
| |
| Institution: | 1. Cawthron Institute , Private Bag 2, Nelson, New Zealand;2. Department of Environmental Science , University of Auckland , Private Bag, Auckland, New Zealand;3. Leigh Marine Laboratory , University of Auckland;4. Cawthron Institue |
| |
| Abstract: | A raphidophyte‐dominated phytoplankton bloom extended discontinuously along the northeastern coastline of New Zealand, from Bream Tail, north of Leigh, to the western coast of the Coromandel Peninsula from late August until December 1992. The bloom was associated with an “El‐Niño” phase of the Southern Oscillation, resulting in unusually cold sea temperatures. The dominant bloom species in the north was Fibrocapsa japonica and in the south Heterosigma akashiwo. Associated species included the coccolithophorid Gephyrocapsa oceanica and the naked form of the silicoflagellate Dictyocha speculum. By December, numbers of the armoured form of D. speculum had increased, as those of raphidophytes and coccolithophorids declined. Bioassays to test for shellfish biotoxins were negative and Artemia salina bioassays, indicators of ichthyotoxicity, were negative except for Heterosigma akashiwo cultures, isolated from Coromandel water samples. |
| |
| Keywords: | Fibrocapsa japonica Heterosigma akashiwo raphidophyte Dictyocha speculum silicoflagellate Gephyrocapsa oceanica climate coccolithophorid phytoplankton bloom |
|
|
